Singtronic is one of the Leading companies in the karaoke industry that makes high end quality digital echo key pitch control karaoke mixers, processor & pre-effects built in 5.1 Channels XLR Output (Main: Left & Right, Surround: Left & Right, Center & Subwoofer) Also with many Digital inputs like Optical, with Bluetooth Function are offer online at the best price on the net. Singtronic DSP-2000Pro is Digital Karaoke Mixer Processor that built in Anti-Howling & Feedback Supressional make karaoke purpose to another high level. This Singtronic DSP-2000Pro Karaoke Mixer Processor is an revolution of the next karaoke generation.